defmodule BitcoinLib.Script.Opcodes.Arithmetic.OneSub do
@moduledoc """
Based on https://en.bitcoin.it/wiki/Script
Word OP_1SUB
Opcode 140
Hex 0x8c
Input in
Output out
1 is subtracted from the input.
"""
@behaviour BitcoinLib.Script.Opcode
defstruct []
alias BitcoinLib.Script.Opcodes.Arithmetic.OneSub
@type t :: OneSub
@value 0x8C
@doc """
Returns 0x8c
## Examples
iex> BitcoinLib.Script.Opcodes.Arithmetic.OneSub.v()
0x8c
"""
@spec v() :: 0x8C
def v do
@value
end
@doc """
Returns <<0x8c>>
## Examples
iex> BitcoinLib.Script.Opcodes.Arithmetic.OneSub.encode()
<<0x8c>>
"""
@spec encode() :: <<_::8>>
def encode() do
<<@value::8>>
end
@doc """
b is subtracted from a.
## Examples
iex> BitcoinLib.Script.Opcodes.Arithmetic.OneSub.execute(
...> %BitcoinLib.Script.Opcodes.Arithmetic.OneSub{},
...> [7, 3, 1]
...> )
{:ok, [6, 3, 1]}
"""
@spec execute(OneSub.t(), list()) :: {:ok, list()}
def execute(%OneSub{}, [first] ++ remaining) do
{:ok, [first - 1 | remaining]}
end
end